Safety valve



Feb. 20, 1951 c. F. BOYER 2,542,387

SAFETY VALVE ,Original Filed March '7, 1947 2 Sheets-Sheet 1 INVENTORATTORNEYS Feb. 20, 1951 c. F. BOYER 2,542,387

SAFETY VALVE Original Filed March 7, 1947 2 Sheets-Sheet 2 INVENTOR I BYI l ATTORNEYS Patented Feb. 20, 1951 UNITED STATES PATENT OFFICE SAFETYVALVE Charles F. Boyer, Allentown, Pa.

Original application March 7, 1947,- Serial No. 733,239. Divided andthis application August 18, 1948, Serial No. 44,974

1 Glaim. 1

Th s invention relates to safety valves, and more particularly, hasreference to a safety valve arrangement for pneumatic tools.

The present application i a division of my co-pending application, filedMarch 7, 1947, and bearing Serial Number 733,239, now Patent Number2,471,604.

The main purpose of the present invention is to provide a safety valvearrangement for pneumatic riveters or chipping machines, and relatedpneumatic tools. It has frequentl happened that a riveting machine leftunattended will be accidentally jarred from its posit-ion, as by someoneaccidentally tripping over the air supply hose leading to the tool. Whenthis occurs, it may be that the tool is set into operation by accidentalengagement of its trigger or operating lever. The tool is thus likely torebound, since it is not being held, and strike nearby persons. This canand in fact has resulted in serious injury.

It is proposed to attain the objects of the invention by reason of theprovision of a novel type of safety valve construction, whereby thepossibility of the tool being accidentally set into operation will beeliminated.

With the foregoing and other objects in view which will appear as thedescription proceeds, the invention consists of certain novel details ofconstruction and combinations of parts, hereinafter more fully describedand pointed out in the claim, it being understood that changes may bemade in the construction and arrangement of parts without departing fromthe spirit of the invention as claimed.

Referring to the drawings Figure 1 i a view partly in elevation andpartly in longitudinal section, through a pneumatic tool formed inaccordance with the invention.

Fig. 2 is a section taken substantially on line 2-2 of Fig. 1.

Fig. 3 is a section taken substantially on line 3-3 of Fig. 1.

Fig. 4 is a section taken 44 of Fig. 1.

Fig. 5 is a fragmentary perspective view of the sleeve valve and plugembodied in the invention.

Referring to the drawings in detail, the reference character 5designates generally the head of the tool, which is of conventionalformation, and is internally threaded for the purpose of receiving oneend of the barrel (not shown).

The other end of the head 5 is closed, except for openings to bedescribed hereinafter, and extended transversely across the closed endof the head is a tubular member 6, which is preferably substantially online 2. formed integral with the head 5, and with the handle I of thetool, that extends from one end of the tubular member 6 in a directionaway from the head 5, and which is formed at its other end with thecustomary grip 3. The grip 8 is formed at one end with an opening 9which is threaded in order to receive a coupling (not shown) with an airsupply hose.

Recessed in one end of the handle 1, and mounted for reciprocationtherein, is the thumb lever 26, that operates the main valve for thepurpose of supplying air to the valve during normal use of the tool. Themain valve and associated parts have been described in my parentapplication, Serial Number 733,239, and need not be discussed in detailherein. It is believed sufficient to state that under the control of theop rator, in normal use of the tool air is permitted to enter the headof the tool through opening 3!, communicatin between the hollow interiorof handle I and the bore of the tubular member 6.

Referring now to the construction of the safety shuttle valve, there ismovably positioned in the adjacent bore of the tubular member 6 thesleeve or safety shut-off valve 32. One end of the sleeve 32 is open,and is engaged by the spring 33 which is interposed between said end ofthe sleeve, and the adjacent end of the tubular member ii. The other endof the sleeve 32 is closed, as shown at 34, and from this closed end isextended a socket 35, that is formed with a threaded opening 35 in whichis engaged one end of a key 35. The outer wall of the socket 35 isprovided with opposed lugs 31, that are receivable in slots 38 formed inthe inner end Of the plug 39 that is threaded into one end of thetubular member 6, and close the bore formed in said m mber, at that end.

Intermediate its ends, the sleeve 32 is formed with openings 40, thatare adapted to be brought into communication with openings 4! providedin the closed end of the head 5. The particular formation andarrangement of my safety valve is such that when it is opened by theoperator, it can not be accidentally closed. It is to be noted that inthe operation of this valve, the user must first push the key 36'inwardly, in orde to disengage the lugs 3'! from the slots 38 formed inthe inner wall of the plug 39. Having so disengaged the lugs 31, the key36' may then be rotated. in order that the openings 40 will be broughtout of register with the openings 4|, the openings 4| thereby beingclosed off by the wall of the sleeve 32. Thus, no air can enter thebarrel of the tool. It may be noted that by rotation of the key 36', the

lugs 31 are then brought to bear against the inner wall of the plug 39,and the key 3-6 is eiiectively prevented from being forced outwardlyunder the force of the spring 33, until it has been rotated so that thelugs 3'! may enter the slots 38, at which time, the spring 33 willautomatically force the key 36' outwardly and hold it in such position.

What is claimed is:

A safety valve for pneumatic tools comprising a sleeve having one endopen to provide an air inlet and having the other end closed, saidsleeve having a discharge opening formedin its side wall; a reducedextension formed on the closed end of the sleeve and having a centrallydisposed threaded socket; diametrically opposed lugs formed on the sidewall of said extension; a plug formed with a smooth bore counterbored toreceive the extension, said plug having diametrically opposed recessesfor receiving said lugs; an

operating key having a shank a portion of which is smooth for slidableand rotatable contact with the wall of the bore of the plug, the end ofsaid shank being threaded and engageable in the threaded socket; and aspring engaging the open end of the tube and normally urging the tube inthe direction of the plug.

CHARLES F. BOYER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

